What is a Banana Circle?
Banana trees are very hungry plants, requiring lots of nutrients, light,…

The vortex hydroelectric project has now been going for around two and half years and construction of the tank and channels was completed in June 2016. We spent the next few months constructing the first prototype turbine and we connected the first power to the house in August 2016. After six months of testing the system and the electrical control systems, we were achieving a power of around 3.5 kW. This was enough energy to run household appliances, such as the washing machine, freezer, computers, and internet, and most of the workshop tools. However, this was not enough power to pump water up the steep hill from the river or provide for future projects such as the laundry/education centre. Hence, we decided to install a much larger turbine designed to produce around 7.5 kW. During installation of this turbine, we began to encounter problems with the transmission of so much power and after a short time the gearbox failed. We spent some time investigating gearbox options and found an exciting alternative: a magnetic planetary gearbox design that allows contact- and lubrication-free transmission and automatic overload protection. As this seems a perfect solution for our needs, we have invested some months doing complex mathematics and writing a code to design a small prototype magnetic gear to test the concept. Meanwhile, we are running the vortex with small turbine blades to limit the power and a temporary transmission system using rubber belts.